Apparatus or tool for applying coating



Aug. 1 8, 1931. J. J. PREBLE 1,819,116

APPARATUS OR TOOL FOR APPLYING COATING Filed March 13, 1925 Patented Aug. 18, 1931 UNITED STATES PATENT OFFICE JAMES JARVIS PREBLE, OF NEWTON, MASSACHUSETTS; LIVINGSTON S'IEBBINS, AD-

MINISTRATOR F SAID JAMES JARVIS PREBLE, DECEASED, ASSIGNOR T0 SPRAGO, INC., 0] SOMERVILLE, MASSACHUSETTS, A CORPORATIQN OF MASSACHUSETTS APPARATUS 0R TOOL FOR APPLYING COATING Application filed March 13, 1925. Serial No. 15,282.

The present invention relates to an apparatus or tool for applying coating material, and more particularly to a tool for applying a protective coating to the internal surfaces of tubes for boilers, fuel economizers, feed water heaters and the like.

Such tubes become pitted by the corrosive action of the hot gases or water passing therethrough, and in order to prolong their usefulness it has been proposed to apply a protective coating to the internal surfaces thereof after every tube cleaning operation. This protective coating has heretofore proved ineffective to resist corrosion in the tubes principally because no means was available by which the protective coatlng could be applied down into the depressions produced by the pits.

The object of the present invention is to provide an apparatus or tool for applying the protective coating by which the coating may be discharged against the internal surfaces of the tubes along a line normal to the longitudinal axis thereof, thus to insure the deposit of the'coating into the pits in a most effective manner.

spection'of the accompanying drawings illustrating the best vform of the invention at present devised, in which, I

Figure 1 is an elevation of the apparatus or tool for applying the protective coatlng to boiler tubes, the hose pipes and guide being broken away to economize space;

Fig. 2 is a front elevation;

Fig. 3 is a central sectional elevation, the hose and guide being removed;

Fig. 4 is a front elevation with the outer nozzle removed, the body of the tool being broken away for convenience, and

Fig. 5 is a rear elevation, of the guide which guides the tubes.

Referring to the drawings the apparatus or tool for applying the protective coating to tubes comprises a body 6 having on its rear end face a threaded opening 7 to which is fitted a hose pipe 8 which conducts the protective coating material from a suitable source of supply (not shown). The rear end face of the body 6 also is provided with a threaded opening 9 to which is fitted a hose pipe 10 which conducts the motive agent under pressure, such as air or steam, from a suitable source of supply (not shown) for dischargingthe protective coating from the tool.

The motive agent under pressure, entering through the opening 9, passes through a passage 11 into a central chamber 12 arranged in the longitudinal axis of the body 6. The chamber 12 is provided with a shoulder 13, a neck 14, and a closed mouth 15. The shoulder 13, hereinafter termed the inner nozzle, is provided with a circular series of outwardly directed apertures 16 arranged at an inclination to the longitudinal axis of the too The neck 14 protrudes through an outer nozzle 17 which is dome-shaped and arranged with relation to the shoulder or inner nozzle 13 to provide a space therebetween. The outer nozzle 17 has a peripheral rim 18 which fits against a vertical seat 19, of reduced diameter, formed on the front end face of the body 6. The outer nozzle 17 is held in place fiatwise against the forward end of the body (3 by a suitable locking means shown as an internally threaded collar or nut 20 having an inturned flange 21 to engage the rim 18.

The protective coating which flows into the body 6 through the opening 7 either under pressure or under the influence of gravity or the suction of the motive agent, passes through the passage 22 into the space between the inner and outer nozzles. The outer nozzle 17 is provided with a circular series of apertures 23 each one of which is arranged in linewith one of the apertures 16. To insure this alignment the rim 18 carries a pin 24 in reduced scale, the tool through which engages a hole 25 formed in the seat 19. The film of coating material formed in the space between the inner and outer nozzles is discharged through the apertures 23 in the outer nozzle by the motive agent discharged through the apertures 16 in the inner nozzles. Each aperture 23 constitutes an individual discharge for the atomized coating. As the apertures 16 and 23 are formed on lines radiating from a common point located in the longitudinal axis of the body 6 the coating material discharged through the apertures will mingle so that the combined discharge of all theapertures 23 forms a cloud having a solid frusto-conical formation, the smaller base of which is adjacent the outer nozzle 17 This cloud of discharged coating will strike the internal surface of a tube some distance from the discharge end of the tool and at an inclination to a line normal to the longitudinal axis. The main discharge of coating material, owing to the inclination at which it strikes the internal surface of the tube, may not reach down into the depressions produced by the pits and thus may not be effective to coat the seat of corrosion in the pit.

In order to make the discharged coating materialimpinge diametrically against the internal surface of a boiler tube and thus insure the coating reaching the seat of corrosion in each pit the neck 14 is provided with a circular series of apertures 26, arranged normal to the longitudinal axis of the tool, through which the motive agent may be discharged supplementally upon the discharged coating material. The supplemental discharge of motive agent through the apertures 26 forms a vertical air curtain at a substantial distance from the outer nozzle 17. The advance of the discharged coating material is thus partially arrested and its frustoconical formation changed suddenly into a hollow cylinder having a diameter equal to the internal diameter of the tube and having one base lying in the vertical plane of the supplemental discharge. In changing the frusto-conical formation into a hollow cylin der the air curtain bells the discharged coating material outwardly away from the extended longitudinal axis of the tool. The

, discharged coating material is thereby caused to strike diametrically against the internal cylindrical surface of the tube thus insuring that the'whole surface of the pits in the tube will receive the proper amount of protective coating. The discharged coating material, which is atomized by the main discharge of motive agent, is further atomized by the supplemental motive agent discharge.

In order to guide the tool through the tube the hosepipes 8 and 10 carry a split cylindrical block 27 having a diameter sufficiently smaller than the internal diameter of a tube to permit the guide to pass through the tube without binding and at the same time maintain the longitudinal axes of the tube and tool substantially coincident.

In using the tool to apply a protective coating to the internal surface of a tube the tool is inserted into one end of the tube with the supply of coating material and motive agent under pressure shut-off. The tool is then, together with the attached hose pipes 8 and 10, fed into the tube until the tool reaches the opposite end thereof. The coating material and motive agent supply are then opened and the tool is then pulled back through the tube. This operation is repeated for every tube in the boiler, fuel economizer, feed water heater or the like, and should be performed after each tube cleaning operation.

lVhile the invention has been illustrated and described in connection with a tool for applying a protective coating to the internal surface of a tube for boilers, fuel economizers, feed water heaters or the like, it will be apparent to those skilled in the art that the tool has a useful application wherever it is desired to discharge a coating in a direction normal to the longitudinal axis of the tool.

It will also be clear to those skilled in the art, with the general objects of the present invention in view, that changes may be made in the details of structure, the described and illustrated embodiment thereof being intended as an exploitation of its underlying essentials, the features whereof are definitely stated in their true scope in the claims herewith.

\Vhat is claimed as new, is:

1. A tool for applying coating comprising a body having inner and outer nozzles each perforated and having surfaces in juxtaposition, means to supply the coating material between said surfaces and to supply a motive agent through said nozzle-s thereby effecting the discharge of the coating material, and means normal to the longitudinal axis of the tool and constituting an extension of the inner nozzle for discharging a supplemental supply of the motive agent upon the discharged coating material.

2. A tool for applying coating material having, in combination, an outer nozzle provided with a circular series of apertures, an inner nozzle spaced from the outer nozzle and provided with a circular series of apertures, the apertures in both series radiating from a common point located in the longitudinal axis of the tool, means to supply the coating material to the space between the nozzles and to supply a motive agent through the inner nozzle thereby to effect the discharge of the coating material through the outer nozzle, and means radiating from the longitudinal. axis of the toolfor discharging motive agent supplementally upon the discharged coating V material.

3. A tool for applying coating material having, with a circular series of apertures, a tube protruding through the nozzle, said tube having on one side of the nozzle a circular series of apertures spaced from the apertures in the nozzle and aligned therewith and having a closed end on the other side of the nozzle, means to supply the coating material to the space between the apertures in the tube and nozzle, means to supply the tube with a motive agent thereby effecting the discharge of the coating material through the apertures in the nozzle, and a circular series of apertures in the tube between its closed end and the nozzle for supplementally discharging motive agent upon the discharged coating material.

4. In an apparatus or tool for applying coating, a motive agent tube having a closed end, a series of apertures arranged at an inclination to the longitudinal axis of the tube, and a second series of apertures, intermediate the closed end of the tube and the first series, arranged normal to the longitudinal axis of the tube.

5. A tool for applying coating material having, in combination, an inner nozzle and an outer nozzle provided with a circular series of apertures, the apertures in both series radiating from a common point in the longitudinal axis of the tool, and a third circular series of apertures radiating from a common point in the longitudinal axis of the tool, said points being spaced apart with both the noz-- zles between them. or

6. An apparatus or tool for applying coating having, in combination, a motive agent passage having a closed end and a circular series of apertures arranged at an inclination to the longitudinal axis of the passage, and a discharge nozzle provided with a circular series of apertures aligned with the series of apertures in the passage.

' 7. In an apparatus or tool for applying coating, a motive agent passage having a shoulder, a neck and a closed mouth; a circular series of apertures in the shoulder, and a circular series of apertures in the neck.

8. A tool for applying coating having, in combination, a motive agent passagehaving a shoulder, a neck and a closed mouth; a circular series of apertures in the shoulder; a circular series of apertures in the neck, and a nozzle spaced from said shoulder and having a circular series of apertures aligned with the apertures in the shoulder.

9. A tool for applying coating having, in combination, a motive agent passage having a shoulder, a neck and a closed mouth; a circular series of apertures in the shoulder, directed outwardly at an, inclination to the longitudinal axis of the tool; a circular series of apertures in the neck normal to the longitudinal axis of the tool, and a nozzle spaced from said shoulder and having a circular sein combination, a nozzle provided ries of apertures aligned with the apertures in the shoulder.

In testimony whereof I have signed my name to this specification.

JAMES JARVIS PREBLE. 

